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💏intro to chemistry review

Secondary (2°) Alcohols

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Secondary alcohols, also known as 2° alcohols, are organic compounds where the hydroxyl (-OH) group is attached to a carbon atom that is bonded to two other carbon atoms. This structural feature gives secondary alcohols unique chemical properties and reactivity compared to primary (1°) and tertiary (3°) alcohols.

5 Must Know Facts For Your Next Test

  1. Secondary alcohols can be oxidized to form ketones, a process that involves the removal of two hydrogen atoms from the carbon atom bearing the hydroxyl group.
  2. The reactivity of secondary alcohols is intermediate between primary and tertiary alcohols, making them useful synthetic intermediates in organic chemistry.
  3. Secondary alcohols can be prepared by the hydration of alkenes or the reduction of ketones using reducing agents like sodium borohydride (NaBH4).
  4. The presence of the hydroxyl group in secondary alcohols allows for the formation of hydrogen bonds, which influences their physical properties such as boiling point and solubility.
  5. Secondary alcohols are commonly found in a variety of natural and synthetic compounds, including some pharmaceuticals and fragrances.

Review Questions

  • Explain the structural characteristics of secondary (2°) alcohols and how they differ from primary (1°) and tertiary (3°) alcohols.
    • Secondary alcohols have the hydroxyl (-OH) group attached to a carbon atom that is bonded to two other carbon atoms. This structural feature distinguishes them from primary alcohols, where the hydroxyl group is attached to a carbon with only one other carbon bond, and tertiary alcohols, where the hydroxyl group is attached to a carbon with three other carbon bonds. The unique structure of secondary alcohols gives them intermediate reactivity compared to primary and tertiary alcohols, making them useful synthetic intermediates in organic chemistry.
  • Describe the oxidation reaction of secondary alcohols and the product formed.
    • When secondary alcohols are oxidized, they undergo a reaction that involves the removal of two hydrogen atoms from the carbon atom bearing the hydroxyl group. This process converts the secondary alcohol into a ketone, a class of organic compounds characterized by a carbonyl group (C=O) flanked by two alkyl or aryl substituents. The oxidation of secondary alcohols to ketones is an important transformation in organic synthesis and is commonly used to prepare various ketone-containing compounds.
  • Discuss the importance of secondary alcohols in the context of their chemical properties and applications.
    • Secondary alcohols are valuable synthetic intermediates in organic chemistry due to their unique reactivity, which is intermediate between primary and tertiary alcohols. They can be used to prepare a variety of other organic compounds, such as ketones, through oxidation reactions. Additionally, the presence of the hydroxyl group in secondary alcohols allows for the formation of hydrogen bonds, which influences their physical properties and solubility. Secondary alcohols are found in a wide range of natural and synthetic compounds, including some pharmaceuticals and fragrances, highlighting their importance in various fields of chemistry and industry.